Word Classes in First Language Acquisition

Abstract

Abstract Word classes are the building blocks of language constituting a precondition for productive language use and grammar development. How can infants generalize word classes? This has been one of the most burning questions in language acquisition research. Theories range from the assumption of abstract innate word classes to bottom-up approaches explaining word-class generation fully by statistical learning. There is, however, general agreement across theories that children have to extract information about the word classes of their language from the input to build up the language-specific categories. This chapter shows how typologically diverse systems can impact this process for the learner. The challenges for the learner with respect to nominal and verbal systems are highly variable in the languages of the world. This suggests an enormous flexibility of the language learning mind, necessitating a highly intricate ability for pattern detection by infant learners. The chapter reviews research on the two major word classes, nouns and verbs, and presents patterns in the input that facilitate category abstraction. Even though nouns seem to be more prevalent in early acquisition, this is only a general tendency, and there is in fact huge variation across learners of different languages.